Microelectronics package with inductive element and magnetically enhanced mold compound component

ABSTRACT

The present disclosure relates to a microelectronics package with an inductive element and a magnetically enhanced mold compound component, and a process for making the same. The disclosed microelectronics package includes a module substrate, a thinned flip-chip die with an upper surface that includes a first surface portion and a second surface portion surrounding the first surface portion, the magnetically enhanced mold compound component, and a mold compound component. The thinned flip-chip die is attached to the module substrate and includes a device layer with an inductive element embedded therein. Herein, the inductive element is underlying the first surface portion and not underlying the second surface portion. The magnetically enhanced mold compound component is formed over the first surface portion. The mold compound component is formed over the second surface portion, not over the first surface portion, and surrounding the magnetically enhanced mold compound component.

RELATED APPLICATIONS

This application claims the benefit of provisional patent applicationSer. No. 62/333,317, filed May 9, 2016. This application is related toconcurrently filed U.S. patent application Ser. No. 15/287,202, entitled“MICROELECTRONICS PACKAGE WITH INDUCTIVE ELEMENT AND MAGNETICALLYENHANCED MOLD COMPOUND COMPONENT,” the disclosures of which are herebyincorporated herein by reference in their entirety.

FIELD OF THE DISCLOSURE

The present disclosure relates to a microelectronics package and aprocess for making the same, and more particularly to a microelectronicspackage with an inductive element and a magnetically enhanced moldcompound component, and a process to form the magnetically enhanced moldcompound component over the inductive element.

BACKGROUND

Silicon on insulator (SOI) substrates are widely used in formingsemiconductor dies due to the low cost of silicon materials, large scalecapacity of wafer production, well-established semiconductor designtools, and well-established semiconductor manufacturing techniques.However, harmonic generations and low resistivity values of the SOIsubstrates severely limit the SOI's usage in radio-frequency (RF)applications. By using SOI substrates in RF fabrications, an interfacebetween the silicon handle layer and an adjacent dielectric layer willgenerate unwanted harmonic and intermodulation products. Such spectrumdegradation causes a number of significant system issues such asunwanted generation of signals in other RF bands that the system isattempting to avoid. In addition, the relatively low resistivityencountered in the silicon handle layer limits the performance andquality factor of inductive elements embedded in the semiconductor dies,such as inductors, transmission lines and couples, by the generation ofunwanted RF current loss in the silicon handle layer.

Further, with the current popularity of portable communication devices,high speed and high performance transistors are more densely integratedon semiconductor dies. The amount of heat generated by the semiconductordies will increase significantly due to the large number of transistorsintegrated on the semiconductor dies, the large amount of power passingthrough the transistors, and the high operation speed of thetransistors.

Accordingly, there remains a need for improved microelectronics packagedesigns that improve the quality factor and inductance value of theinductive elements, and accommodate the increased heat generation of thesemiconductor dies. In addition, there is also a need to enhance theperformance of the microelectronics package without increasing thepackage size.

SUMMARY

The present disclosure relates to a microelectronics package with aninductive element and a magnetically enhanced mold compound component,and a process for making the same. The disclosed microelectronicspackage includes a module substrate, a thinned flip-chip die with anupper surface that includes a first surface portion and a second surfaceportion surrounding the first surface portion, the magnetically enhancedmold compound component, and a mold compound component. The thinnedflip-chip die includes a device layer with the inductive elementembedded therein, a number of interconnects extending from a lowersurface of the device layer and coupled to the module substrate, adielectric layer over an upper surface of the device layer. Herein, theinductive element is underlying the first surface portion and notunderlying the second surface portion. The magnetically enhanced moldcompound component is formed over the first surface portion. The moldcompound component is formed over the second surface portion, not overthe first surface portion, and surrounding the magnetically enhancedmold compound component.

According to an exemplary process, a precursor package including amodule substrate and a thinned flip-chip die is provided. The thinnedflip-chip die has an upper surface that includes a first surface portionand a second surface portion surrounding the first surface portion. Thethinned flip-chip die is attached to the module substrate and includes adevice layer with an inductive element that is embedded in the devicelayer. Herein, the inductive element is underlying the first surfaceportion and not underlying the second surface portion. Next, a moldcompound component is provided over the second surface portion such thatthe mold compound component does not cover the first surface portion.Finally, a magnetically enhanced mold compound component is providedover the first surface portion to form a microelectronics package. Themagnetically enhanced mold compound component is surrounded by the moldcompound component.

Those skilled in the art will appreciate the scope of the presentdisclosure and realize additional aspects thereof after reading thefollowing detailed description of the preferred embodiments inassociation with the accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The accompanying drawing figures incorporated in and forming a part ofthis specification illustrate several aspects of the disclosure, andtogether with the description serve to explain the principles of thedisclosure.

FIGS. 1A-1B show an exemplary microelectronics package with an inductiveelement and a magnetically enhanced mold compound component according toone embodiment of the present disclosure.

FIG. 2 shows an alternative microelectronics package with an inductiveelement and a magnetically enhanced mold compound component according toone embodiment of the present disclosure.

FIGS. 3A-3B show an exemplary microelectronics package with an inductiveelement and a magnetically enhanced mold compound component according toone embodiment of the present disclosure.

FIGS. 4A-4B show an exemplary microelectronics package with an inductiveelement and a magnetically enhanced mold compound component according toone embodiment of the present disclosure.

FIGS. 5A-5B show an exemplary microelectronics package with multipleinductive elements and a magnetically enhanced mold compound componentaccording to one embodiment of the present disclosure.

FIGS. 6A-6B show an exemplary microelectronics package with multipleinductive elements and multiple magnetically enhanced mold compoundcomponents according to one embodiment of the present disclosure.

FIGS. 7-19 provide exemplary steps that illustrate a process tofabricate the exemplary microelectronics package shown in FIG. 1A.

It will be understood that for clear illustrations, FIGS. 1A-19 may notbe drawn to scale.

DETAILED DESCRIPTION

The embodiments set forth below represent the necessary information toenable those skilled in the art to practice the embodiments andillustrate the best mode of practicing the embodiments. Upon reading thefollowing description in light of the accompanying drawing figures,those skilled in the art will understand the concepts of the disclosureand will recognize applications of these concepts not particularlyaddressed herein. It should be understood that these concepts andapplications fall within the scope of the disclosure and theaccompanying claims.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element such as a layer, region, orsubstrate is referred to as being “on” or extending “onto” anotherelement, it can be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there are no intervening elements present.Likewise, it will be understood that when an element such as a layer,region, or substrate is referred to as being “over” or extending “over”another element, it can be directly over or extend directly over theother element or intervening elements may also be present. In contrast,when an element is referred to as being “directly over” or extending“directly over” another element, there are no intervening elementspresent. It will also be understood that when an element is referred toas being “connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present.

Relative terms such as “below” or “above” or “upper” or “lower” or“horizontal” or “vertical” may be used herein to describe a relationshipof one element, layer, or region to another element, layer, or region asillustrated in the Figures. It will be understood that these terms andthose discussed above are intended to encompass different orientationsof the device in addition to the orientation depicted in the Figures.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes,” and/or “including” when used herein specifythe presence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms used herein should be interpreted ashaving a meaning that is consistent with their meaning in the context ofthis specification and the relevant art and will not be interpreted inan idealized or overly formal sense unless expressly so defined herein.

The present disclosure relates to a microelectronics package having aninductive element and a magnetically enhanced mold compound component,and a process for making the same. FIGS. 1A and 1B provide an exemplarymicroelectronics package 10 according to one embodiment of the presentdisclosure. FIG. 1A shows a cross-sectional view of the exemplarymicroelectronics package 10, and FIG. 1B shows a top view of theexemplary microelectronics package 10. For the purpose of thisillustration, the microelectronics package 10 includes a modulesubstrate 12, a thinned flip-chip die 14, a first magnetically enhancedmold compound component 16, a first mold compound component 18, and asecond mold compound component 20. In different applications, themicroelectronics package 10 may include multiple thinned flip-chip dies.

In detail, the module substrate 12 may be formed from a laminate, awafer level fan out (WLFO) carrier, a lead frame, a ceramic carrier, orthe like. The thinned flip-chip die 14 includes a device layer 22, anumber of interconnects 24 extending from a lower surface of the devicelayer 22 and coupled to the module substrate 12, a dielectric layer 26over an upper surface of the device layer 22, and essentially no siliconhandle layer (not shown) over the dielectric layer 26. Herein,essentially no silicon handle layer over the dielectric layer 26 refersto at most 2 μm silicon handle layer over the dielectric layer 26. Thethinned flip-chip die 14 has an upper surface including a first surfaceportion SP1 and a second surface portion SP2 surrounding the firstsurface portion SP1. In some applications, the upper surface of thethinned flip-chip die 14 is an upper surface of the dielectric layer 26.For other cases, the upper surface of the thinned flip-chip die 14 is anupper surface of the thin layer of the silicon handle layer (not shown).The device layer 22 may be formed of silicon oxide or the like, and thedielectric layer 26 may be formed of silicon oxide or the like, whichmay serve as an etch stop in a process to remove the silicon handlelayer (more details in following discussion). Within the device layer22, an inductor 28 and a number of non-inductive elements 30 (such asdiodes, transistors, mechanical switches, and resonators) may beembedded. The inductor 28 is underlying the first surface portion SP1 ofthe thinned flip-chip die 14 and not underlying the second surfaceportion SP2 of the thinned flip-chip die 14. The non-inductive elements30 are underlying the second surface portion SP2 of the thinnedflip-chip die 14.

The first magnetically enhanced mold compound component 16 is formeddirectly over the first surface portion SP1 of the thinned flip-chip die14, while the first mold compound component 18 is formed directly overthe second surface portion SP2 of the thinned flip-chip die 14 and notover the first surface portion SP1 of the thinned flip-chip die 14. Thefirst mold compound component 18 is surrounding the first magneticallyenhanced mold compound component 16. Consequently, the firstmagnetically enhanced mold compound component 16 resides over theinductor 28 and the first mold compound component 18 resides over thenon-inductive elements 30. Because the first magnetically enhanced moldcompound component 16 is adjacent to the inductor 28 and has amagnetically enhanced feature, the first magnetically enhanced moldcompound component 16 may significantly increase the inductance value ofthe inductor 28 and/or improve the quality factor of the inductor 28.Normally, an upper surface of the first magnetically enhanced moldcompound component 16 is coplanar with an upper surface of the firstmold compound component 18. The first magnetically enhanced moldcompound component 16 has a thickness between 1 μm and 400 μm.

The first magnetically enhanced mold compound component 16 may be formedfrom polymer mixed with at least one magnetically enhanced powder, wherethe at least one magnetically enhanced powder may be a ferro-magneticmaterial or a ferri-magnetic material. One exemplary magneticallyenhanced powder is sintered Magnesium-Zinc. Utilizing differentmagnetically enhanced powders, or with different concentrations of onemagnetically enhanced powder, the first magnetically enhanced moldcompound component 16 may have 1.1 times to 1000 times improvement inthe magnetic permeability.

The first mold compound component 18 may be a high thermal conductivitymold compound component and may be formed from a thermoset orthermoplastic material. Compared to a normal mold compound componenthaving 1 w/m·k thermal conductivity, a high thermal conductivity moldcompound component may have 2.5 w/m·k˜50 w/m·k or greater thermalconductivity, such as Hitachi Chemical Electronic Materials GE-506HT.The higher the thermal conductivity, the better the heat dissipationperformance of the microelectronics package 10.

In addition, the second mold compound component 20 resides over themodule substrate 12 and encapsulates at least the sides of the firstmold compound component 18 and the thinned flip-chip die 14. In someapplications, a portion of the first mold compound component 18 mayreside over an upper surface of the second mold compound component 20(not shown). Herein, the second mold compound component 20 may be formedfrom the same or different material as the first mold compound component18. However, unlike the first mold compound component 18, the secondmold compound component 20 does not have a thermal conductivityrequirement in higher performing embodiments. One exemplary materialused to form the second mold compound component 20 is an organic epoxyresin system.

In some applications, the microelectronics package 10 may furtherinclude an underfilling layer 32, as shown in FIG. 2. The underfillinglayer 32 resides over the upper surface of the module substrate 12, suchthat the underfilling layer 32 encapsulates the interconnects 24 andunderfills the thinned flip-chip die 14 between the lower surface of thedevice layer 22 and the upper surface of the module substrate 12.Herein, the second mold compound component 20 resides over theunderfilling layer 32, and encapsulates at least the sides of the firstmold compound component 18, the sides of the dielectric layer 26, andthe sides of the device layer 22. The underfilling layer 32 may beformed from the same or different material as the second mold compoundcomponent 20.

It will be clear to those skilled in the art that other inductiveelements may be embedded in the device layer 22 of the thinned flip-chipdie 14. As shown in FIGS. 3A-3B, a transmission line 28T is embedded inthe device layer 22 and the first magnetically enhanced mold compoundcomponent 16 resides over the transmission line 28T. Further, as shownin FIGS. 4A-4B, a coupler 28C is embedded in the device layer 22 of thethinned flip-chip die 14 and the first magnetically enhanced moldcompound component 16 resides over the coupler 28C.

In another embodiment, as shown in FIGS. 5A-5B, the first magneticallyenhanced mold compound component 16 may reside over multiple inductors28 that are embedded in the device layer 22. Herein, the firstmagnetically enhanced mold compound component 16 is a contiguoussection, which may increase coupling between the adjacent inductors 28.In different applications, other inductive elements (such astransmission lines and couplers) may also reside under the samecontiguous section of the first magnetically enhanced mold compoundcomponent 16. These multiple inductive elements embedded in the devicelayer 22 may be laterally adjacent to each other without overlaps.

In another embodiment, as shown in FIGS. 6A-6B, the thinned flip-chipdie 14 has an upper surface including a first surface portion SP1, asecond surface portion SP2, and a third surface portion SP3. The secondsurface portion SP2 is surrounding the first surface portion SP1 and thethird surface portion SP3, and the second surface portion SP2 mayseparate the first surface portion SP1 from the third surface portionSP3. There is a first inductor 28, which is embedded in the device layer22, underlying the first surface portion SP1 and not underlying thesecond surface portion SP2. Also, there is a second inductor 28′, whichis embedded in the device layer 22, underlying the third surface portionSP3 and not underlying the second surface portion SP2. The firstmagnetically enhanced mold compound component 16 is formed directly overthe first surface portion SP1 of the thinned flip-chip die 14, while asecond magnetically enhanced mold compound component 16′ is formeddirectly over the third surface portion SP3 of the thinned flip-chip die14. The first mold compound component 18 is formed directly over thesecond surface portion SP2 of the thinned flip-chip die 14 and not overthe first surface portion SP1 or the third surface portion SP3 of thethinned flip-chip die 14. Both the first magnetically enhanced moldcompound component 16 and the second magnetically enhanced mold compoundcomponent 16′ are surrounded by the first mold compound component 18.The first magnetically enhanced mold compound component 16 may beseparated from the second magnetically enhanced mold compound component16′ by the first mold compound component 18. In different applications,the first magnetically enhanced mold compound component 16 and thesecond magnetically enhanced mold compound component 16′ may be formedfrom an identical material or formed from different materials. Bydefinition, materials are different if they include different elementsor have a different element composition. Utilizing different materialsor with different concentrations of one magnetically enhanced powder,the first magnetically enhanced mold compound 16 and the secondmagnetically enhanced mold compound 16′ may have different degrees ofmagnetic enhancement. Further, the first inductor 28 and/or the secondinductor 28′ may be replaced by other inductive elements (such astransmission lines and couplers).

FIGS. 7-19 provide exemplary steps to fabricate the exemplarymicroelectronics package 10 shown in FIG. 1A. Although the exemplarysteps are illustrated in a series, the exemplary steps are notnecessarily order dependent. Some steps may be done in a different orderthan that presented. Further, processes within the scope of thisdisclosure may include fewer or more steps than those illustrated inFIGS. 7-19.

Initially, a flip-chip die 14F is attached to an upper surface of themodule substrate 12 as depicted in FIG. 7. For the purpose of thisillustration, the flip-chip die 14F includes the device layer 22, theinterconnects 24 extending from the lower surface of the device layer 22and coupled to the module substrate 12, the dielectric layer 26 over theupper surface of the device layer 22, and a silicon handle layer 34 overthe dielectric layer 26. As such, the backside of the silicon handlelayer 34 will generally be the tallest component after the attachingprocess. Within the device layer 22, the inductor 28 and thenon-inductive elements 30 (such as diodes, transistors, mechanicalswitches, and resonators) may be embedded. The device layer 22 may havea thickness between 4 μm and 7 μm, the interconnects 24 may have athickness between 15 μm and 200 μm, the dielectric layer 26 may have athickness between 0.2 μm and 2 μm, and the silicon handle layer 34 mayhave a thickness between 150 μm and 500 μm. It will be clear to thoseskilled in the art that modifications to these thicknesses may be alsoconsidered within the scope of the concepts disclosed herein.

A second mold compound 20M is then applied over the upper surface of themodule substrate 12 such that the flip-chip die 14F is encapsulated bythe second mold compound 20M as illustrated in FIG. 8. The second moldcompound 20M may be applied by various procedures, such as sheetmolding, overmolding, compression molding, transfer molding, dam fillencapsulation, and screen print encapsulation. The second mold compound20M may be formed from an organic epoxy resin system or the like, suchas Hitachi Chemical Electronic Materials GE-100LFC, which can be used asan etchant barrier to protect the flip-chip die 14F against etchingchemistries such as potassium hydroxide (KOH), sodium hydroxide (NaOH),and acetylcholine (ACH). A curing process (not shown) is followed toharden the second mold compound 20M to form the second mold compoundcomponent 20. The curing temperature may be between 125° C. and 300° C.depending on which material is used as the second mold compound 20M.

Notice that, if the final microelectronics package 10 includes theunderfilling layer 32, which is formed from a different material to thesecond mold compound 20M, there may be extra steps to form theunderfilling layer 32 (not shown) before applying the second moldcompound 20M over the upper surface of the module substrate 12. Formingthe underfilling layer 32 is provided by applying an underfillingmaterial over the upper surface of the module substrate 12 and thencuring the underfilling material to form the underfilling layer 32. Theunderfilling layer 32 encapsulates the interconnects 24 and underfillsthe flip-chip die 14F between the lower surface of the device layer 22and the upper surface of the module substrate 12. The second moldcompound 20M is then applied over the underfilling layer 32, andencapsulates at least the sides of the silicon handle layer 34, thesides of the dielectric layer 26, and the sides of the device layer 22.A curing process (not shown) is followed to harden the second moldcompound 20M to form the second mold compound component 20.

Next, the second mold compound component 20 is thinned down to exposethe backside of the silicon handle layer 34 of the flip-chip die 14F, asshown in FIG. 9. The thinning procedure may be done with a mechanicalgrinding process. The following step is to remove substantially theentire silicon handle layer 34 of the flip-chip die 14F to provide thethinned flip-chip die 14 that has the upper surface at a bottom of afirst cavity 36, as shown in FIG. 10. Herein, removing substantially theentire silicon handle layer 34 refers to removal of at least 95% of theentire silicon handle layer 34, and perhaps a portion of the dielectriclayer 26. As such, in some applications, the thinned flip-chip die 14may refer to a device including a device layer 22, a dielectric layer 26over the upper surface of the device layer 22, and the interconnects 24extending from the lower surface of the device layer 22 and coupled tothe module substrate 12, where the upper surface of the dielectric layer26 is the upper surface of the thinned flip-chip die 14. For othercases, the thinned flip-chip die 14 may refer to a device including adevice layer 22, a dielectric layer 26 over an upper surface of thedevice layer 22, a thin layer (less than 1 μm) of the silicon handlelayer 34 left over the dielectric layer 26, and a number ofinterconnects 24 extending from the lower surface of the device layer 22and coupled to the module substrate 12, where the upper surface of thethin layer of the silicon handle layer 34 is the upper surface of thethinned flip-chip die 14. Removing substantially the entire siliconhandle layer 34 may be provided by an etching process with a wet/dryetchant chemistry, which may be KOH, ACH, NaOH or the like.

Further, the upper surface of the thinned flip-chip die 14 includes thefirst surface portion SP1 and the second surface portion SP2 surroundingthe first surface portion SP1. The inductor 28 embedded in the devicelayer 22 is underlying the first surface portion SP1 and not underlyingthe second surface portion SP2. The non-inductive elements 30 embeddedin the device layer 22 are underlying the second surface portion SP2 ofthe thinned flip-chip die 14.

With reference to FIGS. 11 through 14, a process for providing a firstmold compound component 18 over the second surface portion SP2 of thethinned flip-chip die 14 is illustrated according to one embodiment ofthe present disclosure. After the removing step is done, a molding block38 is placed within the first cavity 36 and over the first surfaceportion SP1 of the thinned flip-chip die 14, as illustrated in FIG. 11.Herein, only the first surface portion SP1 of the thinned flip-chip die14 is blocked by the molding block 38, while the second surface portionSP2 of the thinned flip-chip die 14 is exposed to the first cavity 36.The molding block 38 may be formed from a suitable patternablesacrificial material, such as polyimide, with a height between 2 μm and300 μm. Normally, the height of the molding block 34 is no less than adepth of the first cavity 36.

Next, a first mold compound 18M is applied to substantially fill thefirst cavity 36, and directly contacts the second surface portion SP2 ofthe thinned flip-chip die 14, as illustrated in FIG. 12. The first moldcompound 18M may encapsulate the molding block 38 and reside over anupper surface of the second mold compound component 20, but does notdirectly reside over the first surface portion SP1 of the thinnedflip-chip die 14. The first mold compound 18M may be applied by variousprocedures, such as sheet molding, overmolding, compression molding,transfer molding, dam fill encapsulation, and screen printencapsulation. A curing process (not shown) is followed to harden thefirst mold compound 18M in order to form the first mold compoundcomponent 18. The curing temperature is between 125° C. and 300° C.depending on which material is used as the first mold compound 18M.

The first mold compound component 18 is then thinned to expose an uppersurface of the molding block 38, as illustrated in FIG. 13. The thinningprocedure may be done with a mechanical grinding process. Next, themolding block 38 is removed to form a second cavity 40 and expose thefirst surface portion SP1 of the thinned flip-chip die 14 at a bottom ofthe second cavity 40, as illustrated in FIG. 14. The removal of themolding block 38 may be provided by a dry or wet selective etchingprocess. If the molding block 38 is formed from polyimide, a hot NaOH orKOH solution may be used in selectively removing the molding block 38.

In another embodiment, an alternate process for providing the first moldcompound component 18 over the second surface portion SP2 of the thinnedflip-chip die 14 is illustrated in FIGS. 15-17. After the removal stepis done, the first mold compound 18M is applied to substantially fillthe first cavity 36, and directly contacts the upper surface of thethinned flip-chip die 14, as illustrated in FIG. 15. The first moldcompound 18M may further reside over an upper surface of the second moldcompound component 20. The first mold compound 18M may be applied byvarious procedures, such as sheet molding, overmolding, compressionmolding, transfer molding, dam fill encapsulation, and screen printencapsulation. A curing process (not shown) is followed to harden thefirst mold compound 18M to form the first mold compound component 18.The curing temperature is between 125° C. and 300° C. depending on whichmaterial is used as the first mold compound 18M.

The upper surface of the first mold compound component 18 is thenplanarized, as illustrated in FIG. 16. A mechanical grinding process maybe used for planarization. Next, a portion of the first mold compoundcomponent 18 is removed to form the second cavity 40, as illustrated inFIG. 17. Herein, the first surface portion SP1 of the thinned flip-chipdie 14 is exposed at the bottom of the second cavity 40 and the secondsurface portion SP2 of the thinned flip-chip die 14 is not exposed tothe second cavity 40. The removal of the portion of the first moldcompound component 18 to expose the first surface portion SP1 may beprovided by a laser ablation system.

With reference to FIGS. 18 through 19, a process for providing a firstmagnetically enhanced mold compound component 16 over the first surfaceportion SP1 of the thinned flip-chip die 14 is illustrated according toone embodiment of the present disclosure. As shown in FIG. 18, the firstmagnetically enhanced mold compound 16M is applied to substantially fillthe second cavity 40 and directly contact the first surface portion SP1.A portion of the first magnetically enhanced mold compound 16M mayreside over an upper surface of the first mold compound component 18.The first magnetically enhanced mold compound 16M may be applied byvarious procedures, such as sheet molding, overmolding, compressionmolding, transfer molding, dam fill encapsulation, and screen printencapsulation. A curing process (not shown) is followed to harden thefirst magnetically enhanced mold compound 16M to form the firstmagnetically enhanced mold compound component 16. The curing temperatureis between 125° C. and 300° C. depending on which material is used asthe first magnetically enhanced mold compound 16M.

Finally, the upper surface of the first magnetically enhanced moldcompound component 16 is planarized, such that the upper surface of thefirst magnetically enhanced mold compound component 16 and the uppersurface of the first mold compound component 18 may be coplanar, asillustrated in FIG. 19. A mechanical grinding process may be used forplanarization. Herein, the first magnetically enhanced mold compoundcomponent 16 is surrounded by the first mold compound component 18.

Those skilled in the art will recognize improvements and modificationsto the preferred embodiments of the present disclosure. All suchimprovements and modifications are considered within the scope of theconcepts disclosed herein and the claims that follow.

What is claimed is:
 1. A method comprising: providing a precursorpackage including a module substrate and a thinned flip-chip die with anupper surface that includes a first surface portion and a second surfaceportion surrounding the first surface portion, wherein the thinnedflip-chip die is attached to the module substrate and comprises a devicelayer with a first inductive element that is embedded in the devicelayer, underlying the first surface portion, and not underlying thesecond surface portion; providing a first mold compound component overthe second surface portion such that the first mold compound componentdoes not cover the first surface portion; and providing a firstmagnetically enhanced mold compound component over the first surfaceportion to form a microelectronics package, wherein the firstmagnetically enhanced mold compound component is surrounded by the firstmold compound component.
 2. The method of claim 1 wherein providing theprecursor package comprises: attaching a flip-chip die to an uppersurface of the module substrate; applying a second mold compound overthe upper surface of the module substrate to encapsulate the flip-chipdie; curing the second mold compound to form a second mold compoundcomponent; thinning the second mold compound component down to expose aback side of a silicon handle layer of the flip-chip die; and removingsubstantially the entire silicon handle layer to form the thinnedflip-chip die with the upper surface at a bottom of a first cavity. 3.The method of claim 2 wherein applying the second mold compound isprovided by one of a group consisting of sheet molding, overmolding,compression molding, transfer molding, dam fill encapsulation, andscreen print encapsulation.
 4. The method of claim 1 wherein theprecursor package further comprises a second mold compound componentthat resides over an upper surface of the module substrate, surroundsthe thinned flip-chip die, and extends beyond the upper surface of thethinned flip-chip die to form a first cavity within the second moldcompound component, wherein the upper surface of the thinned flip-chipdie is exposed at a bottom of the first cavity.
 5. The method of claim 4wherein providing the first mold compound component over the secondsurface portion comprises: placing a molding block within the firstcavity and over the first surface portion such that the first surfaceportion is blocked and the second surface portion is exposed to thefirst cavity; applying the first mold compound to substantially fill thefirst cavity and directly contact the second surface portion; curing thefirst mold compound to form the first mold compound component; andremoving the molding block to form a second cavity and expose the firstsurface portion at a bottom of the second cavity.
 6. The method of claim5 further comprising thinning the first mold compound component toexpose an upper surface of the molding block before removing the moldingblock.
 7. The method of claim 5 wherein the molding block is formed frompolyimide with a thickness between 2 μm and 300 μm.
 8. The method ofclaim 5 wherein applying the first mold compound is provided by one of agroup consisting of sheet molding, overmolding, compression molding,transfer molding, dam fill encapsulation, and screen printencapsulation.
 9. The method of claim 5 wherein providing a firstmagnetically enhanced mold compound component over the first surfaceportion comprises: applying the first magnetically enhanced moldcompound to substantially fill the second cavity and directly contactthe first surface portion; curing the first magnetically enhanced moldcompound to form a first magnetically enhanced mold compound component;and planarizing an upper surface of the first magnetically enhanced moldcompound component such that the upper surface of the first magneticallyenhanced mold compound component and the upper surface of the first moldcompound component are coplanar.
 10. The method of claim 9 whereinapplying the first magnetically enhanced mold compound is provided byone of a group consisting of sheet molding, overmolding, compressionmolding, transfer molding, dam fill encapsulation, and screen printencapsulation.
 11. The method of claim 4 wherein providing the firstmold compound component over the second surface portion comprises:applying the first mold compound to substantially fill the first cavityand directly contact the upper surface of the thinned flip-chip die;curing the first mold compound to form the first mold compoundcomponent; and removing a portion of the first mold compound componentto form a second cavity, wherein the first surface portion is exposed atthe bottom of the second cavity and the second surface portion is notexposed to the second cavity.
 12. The method of claim 11 furthercomprising planarizing an upper surface of the first mold compoundbefore removing the portion of the first mold compound.
 13. The methodof claim 11 wherein removing the portion of the first mold compound isprovided by a laser ablation system.
 14. The method of claim 11 whereinapplying the first mold compound is provided by one of a groupconsisting of sheet molding, overmolding, compression molding, transfermolding, dam fill encapsulation, and screen print encapsulation.
 15. Themethod of claim 11 wherein providing a first magnetically enhanced moldcompound component over the first surface portion comprises: applyingthe first magnetically enhanced mold compound to substantially fill thesecond cavity and directly contact the first surface portion; curing thefirst magnetically enhanced mold compound to form a first magneticallyenhanced mold compound component; and planarizing an upper surface ofthe first magnetically enhanced mold compound component such that theupper surface of the first magnetically enhanced mold compound componentand the upper surface of the first mold compound component are coplanar.16. The method of claim 15 wherein applying the first magneticallyenhanced mold compound is provided by one of a group consisting of sheetmolding, overmolding, compression molding, transfer molding, dam fillencapsulation, and screen print encapsulation.
 17. The method of claim 1wherein the first magnetically enhanced mold compound component isformed from polymer mixed with at least one magnetically enhancedpowder.
 18. The method of claim 17 wherein the at least one magneticallyenhanced powder is ferro-magnetic material or ferri-magnetic material.19. The method of claim 17 wherein the at least one magneticallyenhanced powder is sintered Magnesium-Zinc.
 20. The method of claim 1wherein the first mold compound component has a thermal conductivitybetween 2.5 w/m·k and 50 w/m·k.
 21. The method of claim 1 wherein thethinned flip-chip die further comprises a dielectric layer over thedevice layer and a plurality of interconnects extending from a lowersurface of the device layer and coupled to the module substrate.
 22. Themethod of claim 21 wherein the upper surface of the thinned flip-chipdie is an upper surface of the dielectric layer.